I myself only wonder about pdf reflow. My stupid phone which I hate can do it, so it would be nice if my ereader could do it. I don't know why it doesn't. Politics maybe as it could have an app for reading pdfs like phone does. I don't think it's that difficult.
Although, I resigned to converting all my library to mobi files (maybe I should start now as it will take ages
especially with pds as I will have to do it one by one)